Effect of sufentanil postconditioning on level of cathepsin B in myocardium during ischemia-reperfusion in rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of sufentanil postconditioning on the level of cathepsin B in the myocardium during ischemia-reperfusion (I/R) in the rats.Methods Eighteen healthy adult male Sprague-Dawley rats,weighing 250-300 g,were divided into 3 groups (n=6 each) using a random nunber tableshamn operation group (group S),group I/R and sufentanil postconditioning group (group SP).The rats were anesthetized with intraperitoneal 20％ urethane 5 ml/kg.Myocardial I/R was induced by occlusion of the left anterior descending branch of the coronary artery for 30 min followed by 120 min reperfusion.At 5 min before reperfusion,sufentanil 1.0 μg/kg was intravenously injected in group SP,and the equal volume of normal saline was given instead in S and I/R groups.At the end of reperfusion,blood samples from the abdominal aorta were collected for determination of serum cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) concentrations,and myocardial specimnens were obtained for examination of the ultrastructure of cardiomyocytes (using transmission electron microscopy) and for determination of Beclin1,microtubule-associated protein 1 light chain 3 Ⅱ (LC3 Ⅱ) and cathepsin B expression (by Western blot) and cathepsin B activity (by fluorometric assay).Results Compared with group S,the serum cTnI and CK-MB concentrations were significantly increased,the expression of Beclin-1,LC3 Ⅱ and cathepsin B was up-regulated,and the activity of cathepsin B was enhanced in I/R and SP groups (P＜0.05).Compared with group I/R,the serum cTnI and CK-MB concentrations were significantly decreased,the expression of Beclin-1 and LC3 Ⅱ was down-regulated,the expression of cathepsin B was up-regulated,and the activity of cathepsin B was enhanced (P＜0.05),the pathological changes of myocardial tissues were signifieantly attenuated,and autophagosomes were reduced in group SP.Conclusion The mechanism by which sufentanil postconditioning inhibits cardiomyocyte autophagy during myocardial I/R is probably related to increased expression and activity of cathepsin B in rats.